In recent years, a mounting method known as a so-called chip on glass (COG) technology, in which a driving circuit (hereinafter, referred to as a driver IC) serving to drive a display panel is directly mounted on a glass substrate of the display panel, is employed in order for a display device to be formed smaller and thinner.
For example, Japanese Patent Application Laid-open No. 2012-98464 discloses a liquid crystal display device in which a driver IC serving to drive data lines and a driver IC serving to drive gate lines are directly mounted on a thin film transistor (TFT) substrate. In the liquid crystal display device, each driver IC is electrically connected to the data lines or the gate lines via lead-out lines which are connected to terminals of each driver IC.